FOURTEENTH ANNUAL YEAR BOOK— PART XT. 843 



from Scott county. Its prosence there is doubtful. Its occurrence in tlie 

 state seems doubtful. 



In September after tiie rains there was some white rust {Cystopus 

 candidtis) on the radish. Gooseberry rust {Aecidium Grossulariac) was 

 abundant on cultivated gooseberries in Fayette county and common on 

 wild gooseberries in many parts of the state. 



The black knot of the plum (Ploivrightia morbosa) is common wher- 

 ever the European Damson's plums are cultivated; it was common on 

 wild plums of Pruniis Avicricana in Winnebago county (Bakke), and 

 Allamakee and Clayton counties (Pammel). Plum pocket {Exoascus 

 Pruni) was abundant on Prunus Americana in Allamakee, Fayette, and 

 Clayton counties. The Exoascus communis produces swollen branches 

 on the Miner plum, reported only from a few places (Boone county), 

 but probably widely distributed in the state. 



Brown rot (Sclerotmia fructigena) was far less common this year than 

 in 1912. Some occurred on the peach, plum, and apple and early during 

 the season some reported- on the cherry and young branches of Crataegus. 



Raspberry anthracnose (GJoeosporiiwi veneUini) was reported from dif- 

 ferent localities in the state. 



The sycamore blight {Gloeosporkim nervisequum) was reported from 

 many counties where the sycamore is native. This disease manifested 

 itself by the dying of the young shoots giving to the trees the appear- 

 ance of having been nipped by frost. The disease appeared after a wet 

 cold spell followed by warm weather. 



Some early blight {Macrosporiiim Solani) was reported from central 

 Iowa, Scott and Muscatine counties. The dying of young potato shoots 

 in the field was reported from Scott and Muscatine counties. The shoots 

 contained Fusarium sp. 



Of the diseases of grain attention may be called to the presence of 

 Piiccinia graminis on the leaf sheaths of wheat, and oats, but not so 

 destructive as In wet years. The Puccinia rubigovera was somewhat more 

 destructive in leaves of wheat. There was also some P. coronata on oat 

 leaves and some corn rust {Puccinia sorghi) on sweet and field corn, and 

 some P. graminis on red top and. some P. phlei-pratensis on timothy. 



There was also some clover rust (Uromyces Trifolii) on red clover 

 and late in the season some alfalfa rust {TJromyces stritus) on alfalfa 

 though not as abundant as in 1911 and 1912. 



The leaf spot of alfalfa (Phacidium medicaginis) was abundant wher- 

 ever alfalfa is grown. Reported as abundant in Scott, Story, Harrison, 

 and Pottawattamie counties in Iowa. 



There was much silvertop {Sporotrichumi sp.) in Fayette, Allamakee, 

 Clayton and Bremer counties, in some cases as much as 40 per cent of 

 the "seed stalks" were killed. On an average of 25 per cent of the 

 stalks were diseased. There was, however, little of the disease in central 

 and southern Iowa. 



In regard to the diseases of forest trees in addition to the sycamore 

 blight mentioned above, the box elder, especially in wounds, there was 

 much of Pleuroihs ulmarius in Story, Marion, and Buena "Vista counties. 

 The usual amount of Melampsora salicis and Phyllachora ulmi occurred 

 There was much of Marsonia juglandis on the black walnut in central 

 and northern Iowa. 



